If A has complex entries r and s,
sort orders them according to the
following rule: r appears before s in
sort(A) if either of the following
hold:

• abs(r) < abs(s)
• abs(r) = abs(s) and angle(r) < angle(s)

换句话说,首先基于这些条目的absolute value(即复数量级)对具有复杂条目的数组进行排序,并且基于它们的phase angles对具有相同绝对值的任何条目进行排序.

Python(即numpy)以不同的方式命令.从the documentation Amro linked to in his comment开始：

The sort order for complex numbers is
lexicographic. If both the real and
imaginary parts are non-nan then the
order is determined by the real parts
except when they are equal,in which
case the order is determined by the
imaginary parts.

换句话说,具有复杂条目的数组首先基于条目的实际组件进行排序,并且具有相等实际组件的任何条目基于其虚构组件进行排序.

编辑：

如果要在MATLAB中重现numpy行为,可以使用函数SORTROWS基于数组条目的real和imaginary组件创建排序索引,然后将该排序索引应用于复杂数组值：

>> r = roots(q);  %# Compute your roots
>> [junk,index] = sortrows([real(r) imag(r)],[1 2]);  %# Sort based on real,%#   then imaginary parts
>> r = r(index)  %# Apply the sort index to r
r =
   0.2694 - 0.3547i
   0.2694 + 0.3547i
   0.3369 - 0.1564i
   0.3369 + 0.1564i
   0.3528          
   1.3579 - 1.7879i
   1.3579 + 1.7879i
   2.4419 - 1.1332i
   2.4419 + 1.1332i
   2.8344